Study of the phonology-syntax interface has typically proceeded by asking the following question: what aspects of syntactic structure are relevant for the application of phonological rules? Several years’ study of the question by a number of persons (e.g. Kaisse 1985; Selkirk 1984) suggests that phonological rules may be sensitive, either directly or indirectly, to the surface-syntactic constituent structure – typically through extension of the notion of government or c-command. Phrasal phonological rules do not appear to be sensitive to differences in grammatical relations (e.g. subject vs . object) unless these are encoded as different surface constituent structures. Nor do phrasal phonological rules (as opposed to lexical rules) appear to be sensitive to different syntactic features such as [±noun] or [±wh].